The present invention relates to an elastic crawler shoe which is suitable for use in a tracklaying vehicle such as a construction machine, an agricultural machine or the like.
In a conventional tracklaying vehicle such as a bulldozer, a crawler belt which is made of iron is wound around a plurality of rolling wheels arranged on the upper and lower parts of a track frame and is driven by driven drive sprockets so as to make the vehicle travel. However, the vehicle equipped with such an iron crawler belt damages the surface of a paved public road during traveling. For this reason, recently, what is called a rubber crawler belt system in which many core bars which are made of metal are embedded in an endless rubber belt at regular intervals and are engaged with the drive sprockets, thereby to drive the belt is often adopted.
However, in the case of this rubber crawler belt, since many core bars are embedded in the endless rubber belt, when the rubber belt is damaged resulting from cracks, exfoliation and the others, the rubber crawler belt as a whole needs to be replaced with a new one, and therefore there were problems that running costs on a user side run up and time-consuming maintenance is required.
To overcome the foregoing problems, a crawler belt formed in such a manner that many elastic crawler shoes, each of which is comprised of one core bar and an elastic body bonded to the core bar so as to cover the core bar, are arranged in a longitudinal direction of a crawler is disclosed, for instance, in Japanese Patent Laid-Open Publication No. 8-48269 (1996), International Publication No. WO99/12799 and the others. In the case of this proposed elastic crawler shoe, even when the elastic body of one of the elastic crawler shoes is damaged, only the damaged shoe can be replaced, and therefore this elastic crawler shoe is advantageous in that running costs and time required for maintenance can be cut down.
However, when the above-mentioned conventional elastic crawler shoe is used, for instance, on a pressed snow road in winter, snow covering the road surface gets into a space between right and left crawler belt links, and a phenomenon (which is called xe2x80x9ca packing phenomenonxe2x80x9d) in which the sprocket or the like repeatedly packs down the snow which has gotten into the space problematically occurs. When such a packing phenomenon occurs, the sprocket or an idler cannot engage with the crawler belt links, and the crawler belt comes off as a result.
The present invention addresses the problem discussed above, and aims to provide an elastic crawler shoe which is capable of discharging snow which gets into a space between crawler belt links before a packing phenomenon occurs, thereby circumventing a situation in which a crawler belt comes off.
The above object can be accomplished by an elastic crawler shoe according to the present invention, the elastic crawler shoe comprising a core bar fixed to crawler belt links, each of which is endlessly coupled by means of connecting pins, and an elastic body bonded to the core bar so as to cover the core bar,
the elastic crawler shoe further comprising a projection which is made of an elastic material, the projection being provided so as to protrude into a space which is enclosed by the right and left crawler belt links and the front and rear connecting pins.
According to the present invention, even when snow covering the road surface gets into the space which is enclosed by the right and left crawler belt links and the front and rear connecting pins and is packed down by a sprocket or the like, the projection which is compressed by the packed snow stretches to its original length owing to its own resilience in an area where the crawler belt links become disengaged from the sprocket or the like, thereby discharging the packed snow from within the above-mentioned space. In this way, the snow which has gotten into the space between the crawler belt links is discharged before a packing phenomenon occurs, and a crawler belt can thus be prevented from coming off.
In the present invention, a structure in which a covering member which is made of either iron or resin is bonded to the surface of the projection can be adopted. Thus, even when pebbles and the others get caught between the crawler belt links, the covering member which covers the surface of the projection can prevent the projection from becoming deformed and can prevent the surface of the projection from becoming chipped.
Instead of being covered with the covering member which is made of either iron or resin, the surface of the projection may be formed out of an elastic material whose hardness is higher than that of the main body of the projection.
Moreover, in the present invention, it is preferable that the core bar has a hole, so that the elastic body is unitarily formed with the projection. The elastic crawler shoe the elastic body of which is unitarily formed with the projection therefore has the advantage of being easily molded.
Furthermore, the projection may be detachably mounted on the core bar. Thus, when the projection is damaged, only the projection can be replaced, and this replacement can be carried out with ease. In this case, it is preferable that a core bar for the projection is embedded in the projection and is bolted to the core bar. Thus, the projection can be detached with ease.